The present invention relates to a system for putting plate members (e.g., glass plates) to target positions, particularly to a system for automatically supplying glass plates (standing in a pallet) one by one with high speed into a bending furnace (equipped with hearth beds) in the production of curved glass plates for vehicular and industrial uses.
In the case of bending window glasses for vehicles such as automobiles, it is possible to use various bending methods depending on dimensions and shapes of glass plates. In particular, in the case of producing automotive side window glasses, it is common to use a bending furnace with hearth beds due to its very high productivity.
It is necessary to supply glass plates into such bending furnace by taking a first glass plate positioned at the forefront of glass plates standing in a pallet etc. and then by putting the first glass plate on a conveyor table in a manner to bring the first glass plate into abutment with flights (positioning guides), which are fixed to and driven by a conveyor chain. With this, the first glass plate floating over the conveyor table is guided into the bending furnace by the flights.
Due to very high productivity of a bending furnace with hearth beds, it is necessary to supply glass plates one by one with high speed into the bending furnace, too. This, however, involves some difficulties. For example, when a first glass plate positioned at the forefront of glass plates standing in a pallet etc. is taken with high speed, a second glass plate next to the first glass plate may also be pulled by the first glass plate, due to a temporary reduced pressure between the first and second glass plates. This phenomena “blocking” must be suppressed in order to achieve a high-speed supply of glass plates one by one into the bending furnace. Furthermore, it is necessary to conduct positioning of each glass plate in order to accurately bring each glass plate into abutment with flights.
Japanese Patent Publication JP-A-7-61597 discloses an apparatus for transferring glass plates (standing in a pallet) one by one. This apparatus is equipped with a mechanism for removing each interleaf paper between two glass plates.
Japanese Patent Publication JP-A-11-35150 discloses an apparatus for taking glass plates one by one to safely introduce glass plates into a glass cutting machine, etc.
Japanese Patent Publication JP-A-2000-296435 discloses a method for positioning glass plates with shapes other than rectangle.
Japanese Patent Publication JP-A-6-247594 discloses an apparatus for positioning glass plates with shapes other than rectangle.
Japanese Utility Model Publication JP-U-5-82941 discloses an apparatus for transferring glass plates one by one. This apparatus has a frame, suction cups formed on the frame, and a reference sensor and two additional sensors. These three sensors are disposed at three apexes of a triangle and serve to adjust the angle of the frame relative to a glass plate that is positioned at the forefront of the glass plates.
Japanese Patent Publication JP-A-2-43143 discloses a robotic suction hand for transferring plate members one by one by applying suction.
Japanese Patent Publication JP-A-7-315570 discloses an apparatus for separating a first glass plate at the top of a pile of glass plates from a second glass plate next to the first glass plate by ejecting compressed air.